1. Field of the Invention
The invention concerns construction of a tunnel immersed beneath a body of water.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
Numerous techniques have been proposed for building a tunnel beneath a body of water, generally beneath a body of sea water.
Some techniques concern the case where the tunnel is to be built essentially in the underlying ground at the bottom of the body of water, as illustrated, for example, in publications DE 50 882, JP 9 316 901, GB 348 204, EP 0 899 422, JP 09-273382, JP 2 024 489, U.S. Pat. No. 1,441,698, U.S. Pat. No. 4,889,448.
In fact, a widespread solution in this case consists in using a tunnel boring machine to bore the earth, remove the bored material to the rear of the tunnel boring machine, and build the tunnel in successive sections as the tunnel boring machine advances, as for construction of a tunnel through mountains.
A tunnel built in this manner beneath the bottom of a body of water has the advantage of constituting no obstacle to water traffic but on the contrary, among other disadvantages, requires construction of approach works whose length will be proportional to the depth at which the tunnel lies beneath the bottom of the body of water.